Traction device for rubber-tired vehicle

ABSTRACT

A traction device which includes a pair of guide rollers that are combined with a rubber tire and an endless track and are interconnected by adjustment means which serve to reposition one guide roller relative to the other so as to vary the extent of track available for ground contact.

United States Patent [111 3,801,164 Mazzarins Apr. 2, 1974 TRACTIONDEVICE FOR RUBBER- TIRED VEHICLE [75] Inventor: Janis Mazzarins,Macedonia, Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Nov. 6, 1972 [21] Appl. No.: 304,080

[52] US. Cl. 305/23, 305/30 [51] Int. Cl B62d 55/04 [58] Field of Search305/23, 25, 32, 29, 30; 180/95, 9.52

[56] References Cited UNITED STATES PATENTS 2,426,342 8/1947 Couse180/952 FOREIGN PATENTS OR APPLICATIONS 21,560 8/l920 France 305/2393,942 3/1959 Norway 180/95 58,903 12/1922 Sweden 305/23 PrimaryExaminerRichard J. Johnson Attorney, Agent, or FirmEdward J. Biskup [57]ABSTRACT 3 Claims, 3 Drawing Figures TRACTION DEVICE FOR RUBBER-TIREDVEHICLE During the past several years the four-wheel drive rubber-tiredtractor has become a substantial factor in earthmoving operations. Itsmost successful application is as a front-end loader for loading trucksor hoppers, however, it has also been used for excavating, cleanup andother material handling work. The large pneumatic tires used with thetractor permits it to be driven at a higher rate of speed and prevent itfrom causing any substantial damage to the surface over which it moves.It is a recognized fact, however, that rubber-tired tractors do notenjoy the traction crawler tractors have particularly when used on softground or under muddy soil conditions.

Accordingly, the objects of the present invention are to provide atraction device for a rubber-tired vehicle that improves the flotationability of the tires; to provide a traction device which includes a pairof roller supporting arms that are combined with a rubber tire and anendless track and are interconnected by adjustment means which serve toadjust the position of one arm relative to the other so as to vary theextent of track available for ground contact; to provide an adjustabletensioning arrangement for an endless track that is combined with arubber tire and includes guide rollers located on opposite sides of thetire; and to provide an axle housing supported traction device thatincludes oppositely extending arms each of which carries a guide rollerwhich together with a rubber tire serves as a support for an endlesstrack.

The above objects and others are realized in accordance with theinvention by a traction device which is combined with an axle housing ofan off-highway vehicle. A driven wheel which carries a rubber tire ismounted at each end of the axle housing and a pair of arms are supportedby the axle housing adjacent to and inboard of the rubber tire. Each armextends outwardly along an axis perpendicular to the longitudinal axisof the axle housing and in a direction opposite to the other arm. Aguide roller is rotatably carried by the free end of each arm adjacentthe tire and in longitudinal alignment therewith so as to permit aflexible track to be entrained about the rollers and the rubber tire andprovide a substantially flat lower track section for engaging the groundand serving as traction means. In addition, adjustment means areprovided above and below the axle housing for interconnecting the armsand permitting one arm to be adjustably positioned relative to the otherarm so as to vary the extent of the lower track section available forground contact.

Other objects and advantages of the present invention will be apparentfrom the following detailed description when taken with the drawings inwhich:

FIG. 1 is an elevational view showing a four-wheel drive tractorprovided with traction devices made according to the invention;

FIG. 2 is anenlarged plan view taken on line 2-2 of FIG. I and shows oneof the traction devices incorporated with the tractor; and

FIG. 3 is a view taken on line 3-3 of FIG. 2.

Referring to the drawing and more particularly FIG. 1 thereof, anoff-highway front-end loader vehicle is shown comprising a four-wheeldrive tractor 12 which is equipped at the forward end thereof with abucket 14. The tractor 12 is driven by the usual internal combustionengine, not shown, which is located in the rear compartment area 16 ofthe vehicle. The engine supplies drive through a suitable transmissionand drive line to identical front and rear traction devices 18, two ofwhich are provided on each side of the tractor. As seen in FIG. 2, itwill be understood that each of the front and rear traction devices 18is supported by a transversely extending axle housing 20 within which asuitable drive axle 21 is rotatably supported for connection with afinal drive. As is conventional, the final drive consists of a planetarygear arrangement located within a final drive housing 22 which is a partof the wheel that supports a rubber pneumatic tire 24.

The rubber tire 24 is part of the traction device 18 made according tothe invention and as seen in FIGS. 2 and 3, each traction deviceincludes a pair of L- shaped arms 26 and 28 each of which is formed witha tapered body portion 29. The larger end of the tapered body portion 29has a pair of vertically spaced ears 30 and 32 and a cylindrical bearingsurface 34 formed thereon. The opposite or smaller end of the bodyportion 29 has a stub axle 36 which supports a guide roller 38 forrotation about an axis located to one side and below the rotational axisof the wheel and in longitudinal alignment with the rubber tire 24. Anendless track 39 is entrained about the rubber tire 24 and thelongitudinally spaced guide rollers 38. In the preferred form, the track39 is a flexible band-type track having the inner surface thereoffrictionally or otherwise engaging the periphery of the rubber tire 24to be driven thereby.

As seen in FIG. 3 the bearing surfaces 34 of the arms 26 and 28 matewith a complementary cylindrical machined surface 40 formed on the axlehousing 20 inboard of the rubber tire 24. The arms 26 and 28 areinterconnected by four identical threaded stud members which arearranged in sets of two located above and below the rotational axis ofthe drive axle 21. An intermediate part of each stud member 42 isrigidly formed with a collar 43 which is hexagonal in cross section soas to permit the stud member to be rotated about its axis by a wrench.Both ends of each stud member are threaded with one end of being formedwith right hand threads while the other end is formed with left handthreads.

Each of the upper stud members 42 is threadably received by acylindrical pin 44 rotatably supported within each car 30 of the arms 26and 28. Similarly, each end of the two lower threaded stud members42 isthreadably received by a cylindrical pin 46 mounted within each ear 32of the arms 26 and 28. Each of the pins 44 and 46 is supported by theassociated ear for rotation about its longitudinal center axis.

From the above description, it should be apparent that when it isdesired to decrease the amount of track in contact with the ground, theupper stud members 42 are rotated in a direction so as to cause theupper ears 30 of the arms to be drawn together and the lower studmembers would be rotated in a direction so as to cause the ears 32 to bespread apart. As a result, the arm 26 is rotated clockwise about theaxle housing 20 while the arm 28 is rotated in acounter-clockwisedirection. Such movement provides for adjustable positioning of theguide rollers 38 with an accompanying decrease in the extent of thelower track section in contact with the ground below the rubber tire 24.Opposite rotation of the upper and lower stud members 42- would providefor movement of the arms 26 and 28 in directions opposite to thosementioned above to a point where the arms 26 and 28 will be returnedabout the axle housing to have the guide rollers 38 located in theoriginal positions shown in FIG. 3. In this position, the lower run ofthe track 39 is substantially horizontal and has the maximum amount ofcontact with the ground and therefore provides for improved traction anddistribution of the weight of the vehicle 10. On the other hand, whenone or both of the arms 26 or 28 is adjusted upwardly relative to theother as explained above, the amount of ground contact between the lowerrun of the track and the ground is decreased with corresponding decreasein flotation and traction ability of the traction device 18.

Various changes and modifications can be made in this constructionwithout department from the spirit of the invention. Such changes andmodifications are contemplated by the inventor and he does not wish tobe limited except by the scope of the appended claims.

What is claimed is:

1. In combination with an off-highway vehicle having an axle housingextending transversely to the longitudinal axis of the vehicle, a drivenwheel carried by the opposite ends of said axle housing, a rubber tiresupported by said driven wheel, a pair of arms supported by said axlehousing adjacent to and inboard of said rubber tire for rotation aboutthe rotational axis of said driven wheel, each of the arms extending ina direction opposite to the other arm and having one end thereof provided with a guide roller positioned adjacent said tire and inlongitudinal alignment therewith and the other end formed withvertically spaced ears, a flexible track entrained about each of saidguide rollers and. said tire so as to provide a substantially flat lowertrack section below said rubber tire for engaging the ground and servingas traction means, and means above and below said axle housing forinterconnecting said ears and permitting each arm to be repositionedrelative to the other arm about said rotational axis so as to vary theextent of said lower track section available for ground contact.

2. The combination set forth in claim 1 wherein said means includes acylindrical pin rotatably mounted in each of said ears and a threadedstud member threadably received by said cylindrical pin.

3. A traction device for an off-highway vehicle having an axle housingextending transversely to the longitudinal axis of the vehicle, saidtraction device being carried by the one end of said axle housing andcomprising a driven wheel including a pneumatic tire, a pair of armssupported by said axle housing adjacent to and inboard of said pneumatictire for rotation about the rotational axis of said driven wheel, eachof the arms extending in a direction opposite to the other arm andhaving a stub axle positioned adjacent said tire and in longitudinalalignment therewith, a guide roller rotatably mounted on said stub axle,a flexible track entrained about each of said guide rollers and saidtire so as to provide a substantially flat lower track section belowsaid rubber tire for engaging the ground and serving as traction means,and a pair of threaded stud members located in planes substantiallyparallel to said longitudinal axis and positioned above and below saidaxle housing for interconnecting said arms and permitting each arm to beadjusted relative to the other arm about said axle housing so as to varythe extent of said lower track section available for ground contact.

1. In combination with an off-highway vehicle having an axle housingextending transversely to the longitudinal axis of the vehicle, a drivenwheel carried by the opposite ends of said axle housing, a rubber tiresupported by said driven wheel, a pair of arms supported by said axlehousing adjacent to and inboard of said rubber tire for rotation aboutthe rotational axis of said driven wheel, each of the arms extending ina direction opposite to the other arm and having one end thereofprovided with a guide roller positioned adjacent said tire and inlongitudinal alignment therewith and the other end formed withvertically spaced ears, a flexible track entrained about each of saidguide rollers and said tire so as to provide a substantially flat lowertrack section below said rubber tire for engaging the ground and servingas traction means, and means above and below said axle housing forinterconnecting said ears and permitting each arm to be repositionedrelative to the other arm about said rotational axis so as to vary theextent of said lower track section available for ground contact.
 2. Thecombination set forth in claim 1 wherein said means includes acylindrical pin rotatably mounted in each of said ears and a threadedstud member threadably received by said cylindrical pin.
 3. A tractiondevice for an off-highway vehicle having an axle housing extendingtransversely to the longitudinal axis of the vehicle, said tractiondevice being carried by the one end of said axle housing and comprisinga driven wheel including a pneumatic tire, a pair of arms supported bysaid axle housing adjacent to and inboard of said pneumatic tire forrotation about the rotational axis of said driven wheel, each of thearms extending in a direction opposite to the other arm and having astub axle positioned adjacent said tire and in longitudinal alignmenttherewith, a guide roller rotatably mounted on said stub axle, aflexible track entrained about each of said guide rollers and said tireso as to provide a substantially flat lower track section below saidrubber tire for engaging the ground and serving as traction means, and apair of threaded stud members located in planes substantially parallelto said longitudinal axis and positioned above and below said axlehousing for interconnecting said arms and permitting each arm to beadjusted relative to the other arm about said axle housing so as to varythe extent of said lower track section available for ground contact.